It's pretty fascinating, it's like they have a playbook, and they run through it in every conversation when their absurd claims are refuted/shown to be wrong. In no particular order:

• flood the thread with maybe/maybe not related memes

• start multiple threads with different questions/answers to existing threads/comments

• claim they have 'crunched the numbers' so they know what they're talking about

• make multiple other absurd assertions instead of proving the assertion they just got called out on.

• claim you haven't done enough research (if you had, you'd know flat earth to be true)

• insult your intelligence

• call you a sheep for believing everything the gov't tells you

• claim you don't have an open mind (because you don't agree with them)

• claim they're 'just investigating with an open mind' (because they're not sheep, they're innovative forward thinkers) (as if that somehow makes retarded claims scientifically accurate)

• Tell a story that begins with "I used to belive in a round earth but then I.....". (as if that gives credence to the validity of their conclusions)
  This is far from the complete list.